I Cloud capacity and I tunes content

This may be a dumb question but I recently got an E-Mail from Apple saying that I had used most of my statutory 5GB cloud storage and I could rent more at a cost of $0.99 per month. I have quite a lot of TV series that I have purchased, watched then deleted and are now showing on I Tunes as currently available for me to download from the Cloud. (Some of them I have downloaded, watched for a second time then deleted again). My question is do these contribute to my cloud storage capacity or is part of a different system where previous purchase can always be downloaded irrespective of the individuals Cloud capacity.